Here is my take on skills related to Naval adventuring and combat - they are from the RAW - no new skills (only new specialisations and a sub-skill under Tradecraft (Seafaring):
Ship-related skills
Tradecraft (Ag or Int):
Seafaring
Seafaring Specialisation options:
Sailing, Rigging, Ship Repair
Nature Lore (Int) Specialisation: Weather Prediction, Fishing
Folklore (Int) Specialisation: S ea Creatures, Legendary Lands
Education (Int) Specialisations: Navigation, Geography
Ballistics (Ag) Specialisation: Ship Gunnery
I also created rules for ship cards as "items" with rules for Naval weapons (cannon, heavy bolt throwers, etc). Here is a sample ship card, created with Strange Eons computer application, for a Dark Elf Corsair ship:
I'll post more if anyone cares.